1. Field of the Invention
The present invention relates to fasteners for use with flexible materials, such as tarps, tent material, and the like. More specifically, the invention relates to fasteners which are temporary and removable, and even more specifically to fasteners which engage a material without puncturing it.
2. Description of Related Art
Over the years, a number of fasteners have been developed for engaging and gripping flexible material, such as tent fabric or a tarp, and connecting it to a structural element, such as a pole. Many such fasteners have been developed specifically for constructing shelter structures, such as tents.
A number of problems have surfaced with known fasteners. Some such fasteners require piercing the material to be engaged in order to function properly. Piercing the material to be engaged and held is undesirable because it tends to weaken the material structurally, and also tends to increase the risk of leakage. Such fasteners obviously have drawbacks in applications requiring protection from the elements and in certain weather conditions, such as high winds and rain.
The present inventor has developed a number of fasteners that do not require piercing the material to be engaged and held. One such fastener, marketed under the name GripClip(trademark), is shown and described in U.S. Pat. Nos. 4,308,647 and 4,175,305. Other such fasteners are shown and described in varying degrees of detail in various tent applications in the inventor""s U.S. Pat. Nos. 3,986,519; 4,099,533; 4,265,260; 4,265,259; 4,414,993; 4,809,726; and 4,944,322.
The present inventor""s previous non-piercing fasteners have certain common characteristics. Each such fastener comprises two pieces. Typically, one piece is positioned on one side of a section of material to be engaged, and the other is positioned on the opposite side. One of the pieces is then tipped and urged completely through an opening in the other piece, with the material between them. The two pieces are sized and shaped such that by turning, twisting, or otherwise positioning the first piece the two pieces become temporarily xe2x80x9clockedxe2x80x9d together with the material engaged between them. By reversing the process the material can be released. At least one of the pieces is provided with structure to fasten to a pole or other structural element via a length of cord or the like.
Although the present inventor""s non-piercing fasteners are completely suitable for the applications for which they were designed, and to which they have been put, they do have certain structural characteristics that may limit their use in some applications. For example, the inventor""s previous fasteners require the ability for one piece of the fastener to be tipped and then inserted completely through an opening or the like in a second piece of the fastener in order to engage and hold the material. This presents no difficulty when applied to tent structures, for example, because the area behind the second piece is typically open and unrestricted, permitting free movement of the first piece completely through the opening in the second. However, in some applications, such open and unrestricted space may not be available or may not exist. One example would be in a construction application, such as a roofing application. In that application, it may be desirable for the second piece of the fastener to be secured to a rigid structure, such as the roof, at least temporarily. In that application, there may be insufficient open space to permit the first piece of the fastener to be inserted completely through the second piece in order to engage and hold the material.
Thus, there is a need for a fastener embodying the positive characteristics of prior fasteners, such as the ability to engage and hold flexible material without piercing it, while also overcoming certain structural and other limitations of previous fasteners. The present invention provides such a fastener.
Accordingly, it is an object of the present invention to provide a fastener that can engage and hold a section of flexible material without piercing the material.
It is also an object of the invention to provide such a fastener that can engage and hold the material in applications where there is insufficient space to insert a first piece completely through a second piece of the fastener.
It is a further object of the invention to provide such a fastener which is suitable for fastening to a rigid structure, either temporarily or permanently, without impairing the ability of the fastener to engage and hold a section of material.
The present invention provides the foregoing and other advantages, which will become clear from a consideration of the following detailed description of the preferred embodiments, together with the drawings. In summary, the invention comprises a removable fastener for holding a section of material. The fastener has a base with a first surface, which may abut a support stucture, and a geometrically-shaped protrusion, which may comprise a substantially elliptical flange, and which is spaced from the first surface. The fastener also has a frame with a geometrically-shaped opening, which may be a first substantially elliptical opening having a first orientation. The protrusion is free to pass at least partially through the opening when the base and frame are in a first orientation wherein the protrusion and the opening are aligned. However, when the base and frame are in a second orientation in which the protrusion and opening are not aligned, the protrusion is blocked from passing through the opening. Thus, the frame and base may be removably coupled together. When a section of material is placed between the frame and base, the frame and base removably hold the material therebetween without piercing the material.
According to another feature of the invention, the opening comprises a second substantially elliptical opening which has a second orientation from the first substantially elliptical opening. The second elliptical opening has a partial occlusion, preferably at opposite elongate ends thereof. According to this feature of the invention, the protrusion is free to pass through the opening when the base and frame are in a first orientation in which the protrusion and first elliptical opening are aligned, but is blocked from passing through the opening when the frame and base are in a second orientation in which the protrusion is aligned with the second elliptical opening. The first and second elliptical openings may be concentric, and the occlusion may comprise a contiguous portion of the frame itself.
According to another aspect of the invention, the first surface of the base may be provided with facilities to affix the base to a support structure. For example, the first surface may be provided with one or more spikes to affix the base to a support structure.
According to yet another aspect of the invention, the frame may be provided with facilities to connect it to other structures, such as guide lines, tensioning lines, or the other structures.